perf session: Add ability to 'skip' a non-piped event stream

perf session: Add ability to 'skip' a non-piped event stream

A piped event stream may contain arbitary sized tracepoint information
following a PERF_RECORD_HEADER_TRACING_DATA event.  The position in the
stream has to be 'skipped' to match the start of the next event.

Provide the same ability to a non-piped event stream to allow for
Instruction Trace data that may also be in a non-piped event stream.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1406143198-20732-1-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>